Leishmania, a flagellated protozoan is responsible for a
wide spectrum of human diseases. The sequencing of Leishmania genome is
currently underway. A large number of genes have been identified and a small
proportion of these have been ascribed functions. However, it is essential to
carry out functional studies in order to utilize the mass of data generated by
the sequencing project. Using DNA microarrays it is possible to study the
expression of thousands of genes at the same time. Microarrays, containing PCR
amplified DNA from a random amplified genomic library of L. major Friedlin
(Ref: Akopyants et al, MBP 113 (2001)), were hybridized with fluorescent probes
made from procyclic and metacyclic RNA. The fluorescent signal showed an
excellent level of signal to noise ratio. The data was normalised for background
and probe intensity. The relative abundance of RNA for each spot was
calculated. We observed statistically significant increase in signal intensity
(1 to 5-folds, p<0.01) in 5% of DNAs with the metacyclics probe. Meanwhile
in procyclics, 1.5 % of DNAs showed 1 to 3 folds increase in signal intensity.
We also carried out flip-dye experiments to take into account the inherent
ability of some species of RNA to bind to a particular dye. Northern blots were
used to corroborate our results. We have identified several of genes
up-regulated in both procyclics and metacyclics.